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Thursday, September 2, 2010

Heart Failure: Everything RT's need to know

So often respiratory therapists are required to give breathing treatments to patients presenting with dyspnea and wheezing, only to find that these breathing treatments fail to work. Among the most common reasons for this failure is a misdiagnosis of asthma when the primary cause of symptoms is actually heart failure.

Okay? The RT Cave participated in an unofficial poll of respiratory therapists, and nearly 80% of them said that the most common symptoms of heart failure is an upper airway expiratory wheeze that is often forced, and often audible. A doctor or nurse orders a breathing treatment and it fails to work. About 80% of therapists claim that this presents the situation of about 80% of breathing treatments performed in emergency rooms.

It's also common on the floors. You are the therapist on duty, and you get called stat to do a breathing treatment on a patient presenting with dyspnea. Upon your assessment, you learn the patient was fine until she went to use the commode. You realize right away that it is not asthma or COPD causing this flare-up, it is heart failure. It is due to the heart being too weak to keep up with the oxygen demands of the body during exertion. It causes dyspnea, sometimes severe dyspnea. The solution is oxygen and rest. Usually, the oxygen supplied during the breathing treatment is all that is needed, not the albuterol.

Okay? So, this is a typical situation that occurs in the hospital setting. Many, many, many, respiratory therapists will note this. Okay? If you are a new therapist, expect to find a seasoned therapist get irritated by this. It will happen. You and the seasoned therapist present to the room, and the seasoned therapist (your preceptor perhaps), says to the nurse," What are the i's and o's?  Has the patient had any Lasix lately? Maybe we need to give lasix? Maybe we need to put a catheter in this patient so she doesn't have to use the commode."

I saw this when I was a student therapist, and a new therapist. Now, today, I am the seasoned therapist, and I do that. Now, I don't complain. I don't do that. But, I do try to educate, not just the nurse, but the new therapist as well. But, usually, I find that the new therapists figure this out on their own. The people I would like to educate are the doctors.

Okay? That said, here is all you need to know about heart failure, if you don't know already.

To understand Congestive Heart Failure (CHF) you must understand the heart. I am sure you know this already, but for those who want a review, this should suffice.

You effectively have two hearts. Your right heart is responsible for pumping blood through your lungs, and your left heart is responsible for pumping blood through your entire body, including your heart and lungs. Your right heart is a relatively small pump that generates a light pressure to pump blood, and the left heart is a strong pump that generates a strong pressure needed to pump blood through the rest of the body.

The right heart is a smaller pump that generates a pressure of about 15. That's all that is needed to pump blood through healthy, compliant lungs. The left heart is a bigger pump that generates a pressure of about 120/80. This is what is needed to push blood through the body. Nothing new here.

You can have a diagnosis of heart failure and have no symptoms on a day to day basis. However, as your heart becomes a weaker pump, you may present with symptoms, such as noted above. The symptoms may present similar to asthma and COPD, and may include dyspnea and wheezing.

Congestive Heart failure usually refers to a is a condition where the left heart becomes unable to pump blood through the body. It is unable to fully oxygenate tissues and organs that work to keep the body functioning as a system. Without adequate blood flow, tissues and organs will fail to perform their jobs, and the body will die.

When a heart is in failure it is unable to maintain an adequate...

Cardiac Output (CO). This is the volume of blood pumped from the heart per minute. CO is the product of both the stroke volume and heart rate.

Stroke Volume (SV). This is the volume of blood pumped from the heart per beat. This is determined by CO minus heart rate times stroke volume.

Heart Rate (HR). This is simply the number of heart beats per minute.

So, by using the formula above, you can see that cardiac output is affected by anything that decreases the heart rate or decreases the strength of the heart, or the ability of the heart to constrict and force blood to the lungs or body, will decrease the amount of blood leaving the heart.

Afterload. This is blood leaving the heart.

Preload. This is blood entering the heart.

Without doing extensive testing, an easy way to measure cardiac output is by taking a blood pressure. And even easier way is by simply taking a pulse.  Since a pulse oximeter measures oxygen saturation using a pulse, a decreasing oxygen saturation can also be an indicator of decreased cardiac output.

As heart failure progresses, and as the heart becomes too weak to effectively pump blood through the body, blood will back up into the vessels in the lungs, thus increasing the...

Pulmonary vascular resistance. This is the blood pressure in the lungs. As this increases, blood will seep out of the blood vessels and into the lungs, causing...

Pulmonary edema. This is fluid in the lungs.

Increased pulmonary vascular resistance actually squeezes airways, causing them to become narrow. This is why heart failure may mimic asthma, as this causes a wheeze. Fluid is also squeezed out of blood vessels into the intrapulmonary spaces. Some of these secretions may work their way up to the upper airways and sit by the vocal cords, thereby causing that forced, audible expiratory wheeze so commonly heard among the heart failure community. This is called a cardiac wheeze, and it used to be called cardiac asthma. This wheeze cannot be treated with a breathing treatment, although this too often is attempted.

What are the causes? 

1. Hypertension: Coronary artery disease is one ailment that causes blood vessels to become narrowed. Years of working hard to pump blood through narrowed vessels can cause the heart to become hypertrophied (enlarged). A large bicep is good, and it's a sign of good health. A large heart is a sign of a weak pump. It is bad. Eventually it will tire and become an ineffective pump. In fact, 60% of heart failure cases are the result of high systemic blood pressure and coronary artery disease.

2. Coronary Artery Disease (CAD): According to the National Heart, Lung and Blood Institute (NHLBI), CAD is a disease whereby plaque builds up inside the coronary arteries (arteries that supply oxygenated blood to the heart) . This plaque build up is called atherosclerosis, and will slowly cause these arteries to narrow, and thus force the heart to work harder to oxygenate itself. This can often lead to portions of plaque to break free, forming a clot in the heart, and causing a Mycardial Infarction, otherwise known as a heart attack (I'm sure you knew that, but just saying). 
3. Mycardial Infarction: This is where plaque from diseased coronary arteries breaks free and blocks blood flow to a part of the heart, causing heart (muscle) tissue in that area to die. This can cause heart failure. In fact, it can cause severe heart failure symptoms, including dyspnea, orthopnea, hypoxia, cyanosis, and even death.

4. Pulmonary Hypertension: This is where the pulmonary vascular resistance increases to a point where it causes the right heart to become hypertrophied. This makes the right heart a weaker pump. This often leads to left heart failure. Causes of this are COPD, cystic fibrosis, and pulmonary fibrosis. I go into more detail in my post, "Links Between COPD and Heart Failure."

5. Cor Pulmonale: This right heart hypertrophy. It means the right heart has become a weak, ineffective pump. This is responsible for 10-30% of admissions for CHF. For more detail, again check out, "Links Between COPD and Heart Failure."

6. Heart Disease: About 30-40% of heart failure is caused by heart disease.

7. Heart Valve Disease: This constitutes about 20% of heart failure. When the valves of the heart fail to work properly, this causes the heart to become a weaker pump.

8. Congenital Heart Defects: These are diseases a person is born with, and you can read about this in my post, "Congenital Heart Anomalies."

9. Drug abuse: Amphetamines, heroin, cocaine and other drugs may actually numb the heart so much that it becomes a less effective pump and ultimately fails.

10. Alcohol Abuse: Years of abusing your body can cause it.

11. Infection: Influenza, mumps, and rabies are infections that can stun the heart, as are various bacterial infections (streptococcal, rheumatic heart disease). Likewise, sepsis (a systemic blood infection) can also weaken the heart's ability to pump blood.

12. Other diseases: Leukemia, neurologic disorders (Duchenne's muscular dystrophy, Multi-system organ failure, Sepsis, Trauma, cardiac tamponade (squeezes the heart), diabetes and obesity. Diseases such as hemochromatosis or amyloidosis that cause the heart to stiffen, thus decreasing the hearts ability to relax.

All of the above can cause the heart to become a weaker pump, thus resulting in a loss of cardiac output, and causing pulmonary edema and other symptoms that mimic asthma. 

What are the treatments for heart failure?

Bronchodilators are a top line treatment for heart failure. Just kidding! However, some studies do show that some bronchospasm may result from heart failure. Some physicians do believe bronchodilators work. Some patients do note "some" improvement after albuterol. However, it does not remedy the heart failure in any cases. You can only treat heart failure with heart failure medicine.

According to the Mayo Clinic, "You can't reverse many conditions that lead to heart failure, but heart failure can often be treated with good results. Medications can improve the signs and symptoms of heart failure."

Treatment for heart failure includes.

  1. Medicine. Medicines used to treat heart failure are those that strengthen the strength and contractility of the heart, such as Digoxin. They also include medicines to lower the blood pressure or to make patients pee, such as Lasix or Bumex. These are medicines that are often taken every day to prevent heart failure symptoms, or to make symptoms less severe when they do occur. For a list of other medicines used to treat heart failure, check out my post, "Heart Failure Medicine).
  2. Lifestyle changes. These would include such things as quitting smoking, eating a healthy diet, limiting salt intake (to lower blood pressure), exercising to the best of your ability, taking your blood pressure medicines as prescribed by your physician, as well as taking all your meds as prescribed. You'll also need to manage stress, manage depression, manage anxiety, lose weight, control diabetes, and lose weight if you're too overweight.
  3. Surgery. Cardiac anomalies,such as leaky valves and tetrology of ferot can be corrected with surgical procedures. 
  4. Supplemental oxygen. This may be needed during exertion and at night while sleeping. 
  5. BiPAP. This reduces preload and afterload to reduce the heart has to do to work. This can often be worn at night time to improve oxygenation and reduce nighttime dyspnea. It can also be used in hospitals to reduce resistance to breathing and make breathing easier in order to buy time for the medicines used by physicians to work their magic. 
  6. Intubation. It is usually not needed if the patient presents to the emergency room in plenty of time to get adequate treatment. Intubation is often avoided by using BiPAP. 

When can heart failure lead to death?
Heart failure, if untreated, can lead to death because other organs of the body will not be receiving enough oxygen. Usually one of the first organs to be effected are the kidneys, which will fail and lose their ability to excrete salts and water, and actually cause your body to retain more fluid. Actually, kidney failure alone can lead to pulmonary edema, or exacerbate it.

Likewise, fluid will back up in the liver, which in turn will fail in its job of removing toxins from the body. Lacking oxygen, the large and small intestines will lose their ability to absorb nutrients, and thus one organ after another will fail, ultimately leading to death.

What are symptoms of heart failure
Heart Failure is a chronic disease, and the ultimate goal of those with this disease is to prevent acute symptoms. However, from time to time, symptoms will occur regardless of treatment. The key is to know the symptoms and to get to the emergency room as fast as you can. Note that the earlier you get to the ER, the greater your chances of recovering.

I have seen from time to time a CHF patient waits too long, and the damage to the body is so bad there is nothing the attending ER doctor can do to save the patient. On the other end of the spectrum, I've seen patients come in early enough where the doctor can treat the symptoms and the patient actually went home the same day.

However, most patients will require at least a brief inpatient stay. That's what you should expect.

As noted by the Mayo Clinic, symptoms of CHF are:

Chronic heart failure symptoms:
  1. Shortness of breath, or dyspnea with exertion, or with minimal activity
  2. Shortness of breath when lying down (called orthopnea). You have to sit up to breath.
  3. Swelling (edema) in your legs or ankles
  4. Rapid or irregular heart beat
  5. Reduced ability to exercise
  6. Increased wheezing that is often audible
  7. Excessive secretions that are white or pink and frothy (call an ambulance if at this point)
  8. Swelling of abdomen (ascites)
  9. Sudden weight gain (from fluid retention)
  10. Lack of apetite
  11. Nausea
  12. Difficulty concentrating or decreased alertness
Acute Heart Failure Symptoms:

  1. Same as Chronic heart failure, but more severe
  2. Sudden fluid buildup
  3. Rapid or irregular heartbeat (palpitations)
  4. Sudden or severe shortness of breath
  5. Coughing up pink frothy secretions
  6. Chest pain, especially if heart failure caused by heart attack
When to see a doctor:

  1. Chest pain
  2. Fatigue and weakness
  3. Rapid or irregular heartbeat
  4. Shortness of breath (dyspnea) when you exert yourself or when you lie down
  5. Reduced ability to exercise
  6. Persistent cough or wheezing with white or pink blood-tinged phlegm
  7. Swelling in your abdomen, legs, ankles and feet
  8. Difficulty concentrating or decreased alertness
What can lead to worsening CHF?
According "Respiratory Disease: Principles of Patient Care," the following can lead to acute heart failure:

A. Patient induced:

  1. Failure to take medicine
  2. Excessive salt intake
  3. High alcohol ingestion
  4. Physical inactivity or over-activity
  5. Emotional stress
B. Infection: Viral or Bacterial (Sepsis)

C. Arrhythmias: Irregular heart beats (palpitations) such as preventricular contractions (PVC), heart block, bradycardia (heart not able to beat fast enough to pump blood), tachycardia (heart working too hard to pump blood will eventually fail)

D. Excessive fluid administration: This can sometimes result after blood transfusions

E. Pulmonary Embolism: A blood clot can form anywhere in the body and work it's way to the lungs, and thus block a portion of the lungs, causing the heart to work extra hard to pump blood to the lungs.

F. High Cardiac Output demand: Anything that causes your heart to beat too fast, such as when your body requires more oxygen than the heart can pump out:

  1. Fever
  2. Anemia
  3. Pregnancy
  4. Hypermetabolism
G. Heart Attack or ischemia: Lack of oxygen to the heart, or an inability of the heart to function.

H. Renal (Kidney) failure: As noted above, the kidneys are responsible for regulating fluid, and as fluid backs up, this can cause the heart to work too hard.

I. Respiratory Failure: As noted above.

J. Liver disease: As noted above.

K. Drug induced Failure: As noted above

L. Environmental Stress: Hyperthermia (Fever) or Hypothermia (excessive cold)So heart failure can be acute, although the workings that cause it have usually been going on for several years. If you can treat the ultimate causes, you can prevent or delay the onset of this disease.

Likewise, if you notice the signs and symptoms of CHF, make sure you notify your doctor immediately. If you notice the signs of acute CHF, get yourself to the emergency room right away. The quicker you seek help, the greater your chances of surviving the episode.

What is the life expectancy of CHF patients?

Actually, about 50% of patients diagnosed with CHF die within 2 years of diagnosis (5), and this is ultimately due to the hearts poor ability to oxygenate tissues of the body, gradually leading to multi organ failure.

Some people, with good care and good compliance with recommended therapies, lifestyle changes, medicines, vigilance of symptoms, and swift action during acute episodes can live much longer. I wrote about this in more detail in this post.

Information for this post came from the following sources:
5. "
Respiratory Disease: Principles of Patient Care," ed. Robert L. Wildins, James R. Dexter, (F.A. Davis Company), Philadelphia.

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